This project is designed to determine the production of aromatic hydroxamic acids in microbial systems characteristic of selected environmental ecosystems. Particular interest is given to sediment surface microbial populations. The chemistry and biochemistry of arylamine, arylhydroxylamine, arylnitroso and arylnitro compounds under such situations is of interest, particularly with respect to the intermediate production of the nitroso oxidation state, which is required in order for hydroxamic acid production to occur via the established biochemical pathway.